Separation of lanthanum and cerium using a coated solvent-impregnated resin

The separation of lanthanum and cerium, using a solvent-impregnated resin (SIR) containing 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester, coated by polyvinyl alcohol crosslinked by either glutaraldehyde or divinyl sulfone, was investigated. Coating of the SIR successfully suppressed leakage of the extractant during adsorption. Glutaraldehyde was found to be a suitable coating crosslinker based on both the pH dependence of adsorption and leakage of the extractant. The coated SIR was applied to chromatographic recovery of the two metals and quantitative adsorption–elution was carried out via the frontal analysis mode. Complete separation of the metals was achieved using gradient elution with a gradual increase in the concentration of a dilute nitric acid. The coated SIR could be reused for repeated adsorption–elution processing.